White J G, Southgate E, Thomson J N, Brenner S
Philos Trans R Soc Lond B Biol Sci. 1976 Aug 10;275(938):327-48. doi: 10.1098/rstb.1976.0086.
The nervous system of Caenorhabditis elegans is arranged as a series of fibre bundles which run along internal hypodermal ridges. Most of the sensory integration takes place in a ring of nerve fibres which is wrapped round the pharynx in the head. The body muscles in the head are innervated by motor neurones in this nerve ring while those in the lower part of the body are innervated by a set of motor neurones in a longitudinal fibre bundle which joins the nerve ring, the ventral cord. These motor neurones can be put into five classes on the basis of their morphology and synaptic input. At any one point along the cord only one member from each class has neuromuscular junctions. Members of a given class are arranged in a regular linear sequence in the cord and have non-overlapping fields of motor synaptic activity, the transition between fields of adjacent neurones being sharp and well defined. Members of a given class form gap junctions with neighbouring members of the same class but never to motor neurones of another class. Three of the motor neurone classes receive their synaptic input from a set of interneurones coming from the nerve ring. These interneurones can in turn be grouped into four classes and each of three motor neurone classes receives its synaptic input from a unique combination of interneurone classes. The possible developmental and functional significance of these observations is discussed.
秀丽隐杆线虫的神经系统由一系列沿着内部皮下嵴排列的纤维束组成。大部分的感觉整合发生在围绕头部咽部的一圈神经纤维中。头部的身体肌肉由这个神经环中的运动神经元支配，而身体下部的肌肉则由一组运动神经元支配，这些运动神经元位于连接神经环的纵向纤维束——腹神经索中。根据它们的形态和突触输入，这些运动神经元可以分为五类。在神经索的任何一点上，每个类别只有一个成员具有神经肌肉接头。给定类别的成员在神经索中按规则的线性序列排列，并且具有不重叠的运动突触活动区域，相邻神经元区域之间的过渡清晰明确。给定类别的成员与同一类别的相邻成员形成间隙连接，但从不与另一类别的运动神经元形成间隙连接。其中三类运动神经元从一组来自神经环的中间神经元接收突触输入。这些中间神经元又可以分为四类，并且三类运动神经元中的每一类都从中间神经元类别的独特组合接收其突触输入。本文讨论了这些观察结果可能的发育和功能意义。
